1. Field of the Invention
The present invention relates to a spring winding machine and, more specifically, to a transmission mechanism for spring winding machine, which enables wire feeding and wire winding to be operated programmably independently without considering any compensation with respect to wire winding and feeding actions.
2. Description of the Prior Art
Various spring winding machines have been disclosed for processing spring wires into springs or the like. U.S. Pat. No. 5,363,831 discloses an exemplar. According to this design, the spring winding machine uses a first servomotor, a second servomotor to turn a belt transmission mechanism and to further move a spring wire forwards and wind the moving spring wire. This design of spring winding machine enables wire feeding and wire winding actions to be simultaneously performed to short spring processing time. However, because it requires high torsional force to rotate the belt transmission mechanism, the capacity of the servomotors is relatively high. In consequence of the use of high capacity servomotors, the spring winding machine is bulky and heavy. Further, regular spring winding machines commonly use spring wires of caliber within 2 mm for making springs. It is not economic to install high capacity motors in a spring winding machine to feed and wind spring wires.
Further, conventional spring winding machines are capable of processing spring wires of different calibers into springs, i.e., a spring winding machine fits spring wires of different calibers. In order to meet this wide application range, the capacity of the motors should be sufficient for moving and winding a full range of spring wires. However, it is not economic to use high capacity motors in a spring winding machine to move and wind a thin spring wire.
In the aforesaid spring winding machine according to U.S. Pat. No. 5,363,681, the coupling structure between the servomotors and movable parts of the spring winding machine is complicated. It is also complicated to maintain the coupling structure. Because wire winding action is performed during wire feeding action, it is necessary to control reversing operation of the servomotor to stop the spring wire from rushing out. Furthermore, because wire winding action and wire feeding action are simultaneously executed, it is difficult to achieve xe2x80x9csynchronous controlxe2x80x9d accurately, resulting in low yielding rate.
The present invention has been accomplished to provide a transmission mechanism for spring winding machine, which eliminates the aforesaid drawbacks. It is one object of the present invention to provide a transmission mechanism for spring winding machine, which requires less installation space. It is another object of the present invention to provide a transmission mechanism for spring winding machine, which is convenient for maintenance and practical for program control without considering any compensation with respect to wire winding and feeding actions. It is still another object of the present invention to provide a transmission mechanism for spring winding machine, which is inexpensive to manufacture. To achieve these and other objects of the present invention, the transmission mechanism for spring winding machine comprises a rotary table, the rotary table having an eccentric main shaft protruded over first and second sides thereof and a driven gear at one end of the main shaft, a wire feeding box fixedly mounted on the second side of the rotary table, the wire feeding box having an intermediate gear, a transfer cylinder set formed of a wire-transfer cylinder and an impression cylinder adapted for transferring a spring wire for processing, a spur gear coaxially connected to the wire-transfer cylinder and meshed with the intermediate gear, a first bevel gear fixedly mounted on the other end of the main shaft, a second bevel gear coaxially connected to the intermediate gear and meshed with the first bevel gear, a wire feeding motor installed in the first side of the rotary table and adapted for rotating the driven gear and the main shaft, and a reversible wire winding motor adapted for rotating the rotary table clockwise/counter-clockwise through 180xc2x0 through a transmission belt.